BIOC192 Lecture 4 - Building blocks of Proteins Flashcards
what 4 components make up the backbone of an amino acid?
1) amino group (NH2)
2) alpha carbon
3) R group (side chain)
4) carboxyl group (carbonyl carbon)
what are the 2 types of amino acid name abbreviations?
1 letter abbreviations and 3 letter abbreviations
what does it mean that amino acids are chiral?
they are attached to a chiral carbon and for a carbon to chiral it needs to have 4 different groups attached
what are the 4 main groups of amino acids?
1) non-polar amino acids
2) uncharged polar amino acids
3) negatively charged (acidic) polar amino acids
4) positively charged (basic) polar amino acids
what are the properties of non-polar amino acids?
the hydrophobic non-polar side chains will fold into the middle of the protein surrounded by the hydrophilic polar side chains to stabilise the protein
where in a protein would you expect to find non-polar amino acid residues?
in the middle of the protein
what chemical groups would you expect to find in the R-group of an ionisable amino acid?
1) OH group
2) NH group
3) SH group
where in a protein would we often find ionisable amino acid residues?
on the R group (side chain)
what is the name of the bond that links amino acids in the polypeptide chain?
peptide bond
what are the key properties of the peptide bond?
the bond is planer, trans, and has a dipole
what is the defintion of pKA?
pH at which the ionisable group is 50% ionised
what is the defintion of pI?
pH at which the net charge of an amino acid or protein is zero
what are 3 common examples of post-translational modifications?
1) phosphorylation
2) hydroxylation
3) carboxylation
what is phosphorylation?
control of enzyme activity often by ON/OFF
what is hydroxylation?
needed to prevent connective tissue diseases and scurvy
